Reciprocating compressors are used in a great many industries, including oil refineries, gas pipelines, chemical plants, natural gas processing plants and refrigeration plants. For example, to transport natural gas from production sites to consumers, pipeline operators install large compressors at transport stations along the pipelines. Natural gas pipeline networks connect production operations with local distribution companies through thousands of miles of gas transmission lines. Typically, reciprocating gas compressors are used as the prime mover for pipeline transport operations because of the relatively high pressure ratio required.
Reciprocating compressors compress fluid using a piston in a cylinder connected to a crankshaft. The crankshaft may be driven by a motor or an engine. A suction valve in the compressor cylinder receives input gas, which is then compressed by the piston and discharged through a discharge valve.
A specific challenge when using high-horsepower, high-speed, variable-speed compressors is failure of the compressor valves. A common type of valve used for reciprocating compressors is a plate-type compressor valve. These valves experience high plate impact velocities that often result in fatigue failures and a short operating life, leading to frequent valve replacement. Studies have identified impact velocity, which is the velocity of the valve plate when it reaches the limit of its travel, as a significant factor in assessing valve life.